We don’t know how well threatened species fight off bird flu – but we need to
As bird flu takes hold, we must find and conserve species with less genetic ability to fight the virus.
Bird flu is spreading in Australia and poses a threat to many native species, according to a recent federal government analysis. The assessment reveals that nearly one in five Australian bird and mammal species are at high, very high or extreme risk of being affected. However, this risk assessment lacks crucial information regarding the genetic makeup of the species and their ability to combat the virus.
Different species possess varying immune systems, and this genetic diversity plays a critical role in determining their ability to fight off the virus.
While some species, like black swans, are expected to be severely impacted, others, such as wild ducks, are likely to fare less well. However, the primary factor behind the differences in susceptibility lies in the variation of immune system genes across populations. Currently, there is no comprehensive overview of the highest-risk species based on this factor. To effectively protect the most endangered animals, creating a national immune-risk map for threatened species is imperative.
The immune gene variations are vital for an animal's defense against a virus. When the virus enters an animal's body, its immune system must detect and respond to it. Key immune genes play a significant role in an individual's ability to survive, become seriously ill, or die from the infection. The diversity of these genes within a species is critical, as it acts as biological insurance against new diseases.
Large wildlife populations often possess a wide array of immune gene variants, which can provide protection when a new disease arrives. However, threatened species often become immunologically fragile due to various threats, including habitat loss, climate change, invasive species, pollution, and disease. These factors contribute to the reduction of genetic diversity, leaving small and fragmented populations with limited genetic diversity to counter new diseases.
Many Australian species, such as the orange-bellied parrot and Tasmanian devils, face the risk of extinction due to low immune gene diversity caused by population bottlenecks. In the case of the orange-bellied parrot, only 86 birds remain in the wild, and captive breeding programs are essential for its survival. Similarly, Tasmanian devils have critically low immune gene diversity, making them vulnerable to contagious diseases, including the facial tumour disease that has caused significant population declines in the past.
Applying a national immune-risk map to these species would enable wildlife managers to establish new captive populations before the virus arrives and minimise inbreeding, thereby protecting them from bird flu and future diseases. It is crucial to act swiftly to identify species and populations with low immune diversity and implement measures before irreversible losses occur.
Written by urgent.news from The Conversation AU's reporting — not their text. Machine-written — it may contain errors, so check the original before relying on it.
